With continuous development of mobile communications technologies, the 5th generation of wireless communications system (5G, the 5th Generation of wireless communication system) supports access of multiple types of terminal devices, including a person-to-person communications device (for example, a smartphone), a machine type device, a vehicle, a drone, a robot, and the like. Different terminals have different service type requirements, and a same terminal also has different service type requirements in different scenarios. For example, a smartphone initiates voice/video call and data services in an entertainment environment, and initiates navigation and self-driving control services in an in-vehicle environment. Different device types or service types have different communication service quality of service (QoS, Quality of Service) requirements for a mobile communications network. For example, the voice/video call and data services require QoS with a high rate and a relatively low delay, and the navigation and self-driving control services require QoS with a relatively high rate and an ultra-low delay.
In addition, the 5G system further supports multiple types of access networks, such as a 3rd Generation Partnership Project (3GPP, 3rd Generation Partnership Project) network and a non-3rd Generation Partnership Project network (such as Bluetooth and a wireless local area network). There are multiple types of access nodes in an access network, such as a base station, a terminal that supports device-to-device (D2D, Device to Device) communication, and a wireless access point (AP, Wireless Access Point). Access nodes in different access networks support different communication types, such as ultra broadband wireless communication (Ultra Broadband Wireless Communication, or referred to as enhanced mobile broadband enhanced Mobile Broadband communication) and machine type communication (MTC, Machine Type Communications). Therefore, QoS (Quality of Service, quality of service) provided by access networks of different types may be different, and QoS provided by different access nodes in a same access network may also be different.
In an existing wireless communications system, when accessing a wireless communications network, a terminal selects, according to a signal status such as signal power or signal quality of the network, a serving cell for accessing the network. However, because of diversified terminal devices and services, the serving cell selected by the terminal according to the signal status may not support a service requirement of the terminal because the serving cell does not support a specific communication type.